Should i ask my girlfriend to marry me?

Some background info. we have been dating since march of 08 and have known each other since jan of the same year. We have practically lived together for more then half that time. i have and 8 yr old son that she met back in august and she instantly fell in love with him, as he did with her. We do almost everything together, we have even recently looked at houses together in her hometown. We have upcoming plans to travel at thinksgiving time for her to meet my grandmother. I have already met her family. i was married for 9 yrs before i met her and there are only about 5 pics of me smiling in those nine years. since i have met her there are maybe only 5 pics where i am not smiling out of over a thousand pics. All my friends who knew me before i met her and see me now all ask me what happen what changed to make you so happy, or they call me names like Mr. Giggles or Smiley! The few people who do know about us and have been around us tell me that we act like we are married already!
The negative side to this whole thing is 1. i am a secret to almost everyone we know. i cant think of one of her male friends that she has who knows that we are seeing each other. 2. she tells me that she never wants to be married again (she was married once before) 3. although we have looked at houses together she tells me that she doesnt want to live with anyone and she doesnt want to share anything with anyone, she wants everything to be hers. 4. in the 2 yrs that we have known each other she has never once told me that she loves me.
there is more but i will go with this for now...
what should i do?